Sheet feeder for printing press



Aug. 5, 1958' l.. MESTRE,

SHEET FEEDER FOR PRINTING PRRss 10 Sheets-Sheet 1 Filed Oct. 12. 1953 I Smaetor- U/S'MESTPE Aug- 5, 1958 MESTRE SHEET FEEDER FOR PRINTING PRESS 10 Sheets-Shes?l 2 Filed oct. 12, 1953 Aug. 5, 1958 L, MESTRE SHEET FEEDER FOR PRINTING PRESS 10 Sheets-Sheet 5 iled oct. 12. 1953 Aug. 5, 1958 L. MESTRE SHEET FEEDER FOR PRINTING PRESS Filed Oct. 12. 1953 10 Sheets-Sheet 4 A@ Gttorneg Aug. 5, 1958 MESTRE SHEET FEEDER FoR PRINTING PREss 7 10 Sheets-Sheet 5 Filed 001'.. 12,1953

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SHEETV FEEDER FOR PRINTING PRESS Filed oct. 12, 195s lO Sheets-Sheet v8 I nnentor ws Masnag- LA Gttorrfe'g Aug. 5, 1958 1 MESTRE SHEET FEEDER EoR PRINTING RREss l 10 Sheets-Sheet 9 Filed OGl'.. 12. 1953 inventor 0/5 MESTRE Aug. 5, 1958 L. MESTRE SHEET FEEDER FOR PRINTING PREss 10 Sheets-Sheet 10 Filed Oct. 12. 1953 INVENTOR.

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. QM @m United rates arent SHEET FEEDER FR PRINTING PRESS Luis Mestre, New York, N. Y., assignor to Lewfor Development Corporation, New York, N. Y., a corporation of New York Application October 12, 1953, Serial No. 385,430

9 Claims. (Cl. 271-31) The present invention relates to a sheet feeder for a printing press and the principal object of the invention is to provide novel and advantageous means of the general character specified.

Another object is to provide novel and advantageous means for picking up sheets from a supply stack.

Another object of the invention is to provide novel and advantageous means for controlling the supply of sheets in a supply stack to a position for pick up by a pick-up device.

Another object of the invention is to provide novel and advantageous suction pick-up means.

Another object of the invention is to provide novel and advantageous air ow means to act on sheets at the top of the stack to facilitate pick up by suction pick-up means.

Another object of the invention is to provide novel and advantageous means for guiding the sheets of the stack during the upward movement of the stack.

Another object of the invention is to provide novel and advantageous means for separating the forward edge of the top sheet from the next lower sheet in the pick-up operation.

Another object of the invention is to provide novel and advantageous feeler means for controlling the operation of the stack feeding means.

Another object of the invention is to provide novel and advantageous means for raising a supply stack comprising a ratchet wheel, an actuating pawl, a pawl carrier for feeding an actuating pawl, a holding pawl for said ratchet and a pawl to cooperate with said pawl carrier and holding it against return movement at a position slightly back of its limiting operating position, means for releasing the pawl carrier when the top of the stack is below the proper level and cam means for operating the pawl carrier which are rendered ineffective by latching-of the pawl in its forward position except for slight forward movement which relieves the pressure on the actuating pawl and on the holding pawl and enables easy release of the pawls at that time.

Another object of the invention is to provide novel and advantageous means for ejecting sheets when more than one sheet is carried forward at one time by the suction pick-up means.

Other objects, features and advantages will appear upon consideration of the following detailed description and of the drawings in which:

Fig. 1 is a front elevation of a machine constituting an embodiment of one form of the invention;

Fig. 2 is a top plan view of the machine illustrated in Fig. l;

Fig. 3 is a View correspondiriD to the upper part of Fig. 1 but with additional parts shown in dotted lines;

Fig. 4 is a rear elevation of the parts of the machine illustrated in Fig. 3 with additional parts shown in dotted lines;

Fig. 5 is a sectional view taken along line 5 5 of Fig- 4;

Fig. 6 is a view similar to Fig. 3 but with the parts in different positions;

Fig. 7 is a section taken-along the line 7 7 of Fig. 2;

Fig. 8 is a section taken along the line 8 8 of Fig. 6;

Fig. 9 is a section taken along the line 9 9 of Fig. 1'

Fig. 10 is a section taken along the line 10 10 Fig. 9;

Fig. 11 is a section taken along the line 11-11 Fig. 8;

Fig. 12 is a section taken along the line 12 12 Fig. 8;

Fig. 13 is a View illustrating parts of Fig. 12 shifted to other positions by the presentation of a plurality of sheets simultaneously;

Fig. 14 is a fragmentary view with parts broken away, illustrating on a larger scale the means for manually disengaging the holding pawl for the stack-lifting ratchet;

Fig. 15 is a view showing a device to engage the rear face of a stack of sheets on a carriage mounted for upward and downward movement;

Fig. 16 is a fragmentary View of the device of Fig. 15 as seen from the right; and

Fig. 17 is a view in elevation of the sheet-supply end of the machine.

Referring to the drawings, a stack 25 of sheets` 26 of suitable material such as paper is placed on a carriage or elevator 27 which is provided at each side with two rollers 28 guided between parallel rails or guides 29.

.Said carriage 27 is raised intermittently by means including chains 3d at each side of said carriage extending upwardly from said elevator along the parallel rails 29. A feeler 31 (Fig. 7) moves down toward the top of the stack following each withdrawal of a topsheet or sheets. If the topsheet is above a predetermined level, there will be no upward feed of the carriage until one or more sheets are taken off the stack to enable the feeler to drop sufi-lciently to render the carriage feed effective. f

Suction ngers 32 engage the top sheet of the stack at :spaced points adjacent the edge of the sheet and with the aid of air jets pick up the topsheet 26 of the stack and place it on a feed roll 33 and beneath cooperative feeding means 131. At this same position (Fig. y12) is a rockable member 34 of a device which becomes operative if two or more sheets Iat a time are introduced to cause the ejection of such sheets from the machine after which said rockable member 34 is restored to normal position. From the feed roll 33 the sheet passes over a second feed roll 35 and beneath balls 250 Fig. 8, mounted for vertical movement and serving to assure friction drive of the `sheet by feed roll 35. From the feed roll 35, the sheet normally passes over an ejector member 37 (Fig. 12) to the upper surface of a band or bands 3S of endless form passing around an adjacent roll 39 and a roll (not shown) of a machine such as an offset printing machine to which sheets are fed by the feeder of the present invention.

Said ejector member or plate 37 is supported at opposite ends by brackets 4i) which `are fixed on a rockshaft 41.' rockable member 34, said ejector member 37 will be rocked counterclockwise sufficiently to direct the sheets to be ejected downwardly into an inclined chute 42. After such ejection the ejector member 37 will be restored to its normal position and following sheets will be fed to said bands 3S for feeding to the printing machine.

Power for operatingv the feeding machine in synchronism with a printing machine is providedby a sprocket,

Also Xed on said shaft 45 is a gear 46 meshing with a gear 47 on a shaft 48 carrying roll 39 which drives the When a plurality of sheets is introduced under.

bands.38. Saidtgear 46 .alsorneshes with a Ygear `49 on a shaft '50 on which feed roll 3S is fixed, said gear 49 being 'of the same size as said gear `47. 'Feed roll'33 is mounted on a shaft 51 having fixed thereon a gear 52 of the same size as gear 49. Gears 49 and 52 connected by 'a gear'53, turn in unison with each other and Ywith gear 47. Consequently the feed rolls 33 and 35 and the banddriving ro1l'39. are driven at the same surface speed.

To .control the action kof the variousiparts of the machine, including theair suction devices and air .jet devices, agear or pinion 54'xed on shaft 50 meshes with alarge gear 55 .on a .cam shaft 56 which extends to the front side of the machine. 'At the front side of the machine, said ,cam shaft 56 has xed thereon .an outer. cam'57 to control said "feeler 31 which forms part of mechanism to assure adjustment of thetop sheet 26 of stack "25V to the proper. level, an intermediatecam 58 to effect stepby-step 'upward movement o'f said elevator 27, and an inner cam 59 (Fig. 7.) to vactuate the suction pick-up fingers .32. 'Saidfinner cam I59- (Fig. l2.) is provided at its outer 'face with a stud `282Ihaving acylindrical outer surfaceto engage and operate a'bell crank lever 280,

281 'to resetthe feeling .or sensing device which causes.

the ejection from the machine of multiple sheets picked up at one time from.the stack.

In'order to 'support or lift said elevator 27, said chain 30 -at vthe front and back of the machine passes over sprockets 62 'at thetop of said guides29 and downwardly and forwardlyto sprockets 63 fixed on a transverse shaft 64. :'Saidchains extenddownwardly along the fronts of said'sprockets 63 'and rearwardly .along the bottoms of said/sprocketsand are held `against said sprockets 63 by rolls 65. From said'rolls 65 -sadchains 30 extend downwardly and are held in verticalpositions by weights 66.

Shaft 64 is actuated to turn sprockets63 andoperate on chains 30 toltsaid-elevator'27. .A relatively large gear 7 0 on the .front end of said shaft 64 serves to rotate said shaft. A'rotatably mounted pinion or .gear 71 meshes with gear 70 to Adrive the latter. Power-is applied to pinion 71 lby means 'of 'a .ratchet or ratchet wheel^72 fixed Ithereto turn about -the same axis. The ratchet Wheel 72 may be operated in 'a 'clockwise ldirection (Fig. 6) '.by an actuating pawl 73pivoted on apawl carrier'74 pivotally mounted to`turn about .the Vsame axis.

fPinion`71 and ratchet72arexed on shaft 75 kand pawlgcarrier74. is mounted toturn about said shaft. Said pawl carrier may begswung counter-,clockwise about its pivot 75by alink 76'of whichthe forward end is.con nected 'by a'pivot178toithe pawl .carrier 74.and a part to therear is `connected ata point'78 toone arm of a bell crank 79 on a;pivot18.0. Pivoted on the other arm .of said bell crankis a.follower 81 for ,engagement with said intermediate cam S. Saidlink'76 is drawn downwardly to the'left by a springiSZ which'tends to move follower 81 'into 'engagement with said intermediate cam 58 on cam'shaftf, and to moverpawl '73 to 'a position for `starting a ,clockwise movement of said ratchet 72. Said spring'82'is illustrated '(Fig. l) as `substantially in alignment With.link76 andconnected at one'end to said link and at the Yother end Y'to a pin`83 on the frame of the machine.

A holding pawl 84lfor the ratchet'wheel 72 is mounted on a`pivot'85 and is urged into engagement with the ratchet byiaspring 86 (Fig.l14) connecting an extension of said holding pawlwith 'a suitablepart such as a pin 87 carriedby'thelframe. Also mounted on said pivot 85 (Fig. 6) is apawl-disengaginglever 83 having a work arm 89 with a .curved or arcuate .upper edge beneath pins 90 and 91 .on actuating pawl '73 landholding pawl 84.respectively, :and a power. arm '92 .on the other side of ,said pivot ,85. Azhand lever 93 is mounted ona pivot 94 andis. normally heldin substantiallyvhorizontal positionby a springf95 yconnectinga raised .endof the inner arm 96 .to said arm 92 and limited in its downwardvmovementtby atlater-al lug-t97 extending across said arm92.

With this structure and no more, a forward movement of pawl carrier 74 would carry the shoulder 98 beyond the hook of pawl 99. A'fter the pawl carrier has had a short return movement, pawl 9.9 engages and holds the pawl carrier and cam 58 moves away from follower 81. The cam-.53 intthelfollowing rotation will engage'follower 81 in its outward position'and thereby rock pawl carrier enough to relieve the pressure on pawl 99 so that it can easily be Yswung Yto ineffective position by lan arm 104 on shaft 105, which is fixed to an arm 106 at one end of a cross bar or feeler 31 (Fig. 2). At the other end, the feeler is carried by an arm 107 pivotally mounted on a stud 108.

For the same lgeneral reasons, downward movementof the outer arm .o'f hand lever 93 will produce lifting of arm 89 only whenthe pressure onpawl 99 is released by the slight movement of pawl carrier 74 by cam 58. Upon such release the Aelevator 271may be moved up ordown by means of hand wheel 1'09which carries a `handle 11G (Fig. .9).

Feeler 31 and arm 104 v.are lifted ateach rotation of cam shaft 46 'by the actionof feeler camv 57 on'follower 111 at 'the end of a downwardly and rearwardly extending arm of a bell crank `112.loosely-mounted on shaft 113. A'link v114 connects a ,pivot 115 at the end of van upwardly extendingarm of the bell crank 112 with a pivot 116, at the end of a ,downwardly .and forwardly extending arm 117 of which the otherend is mounted on shaft to turn the same. vDownward .movement of feeler 31 and arm A104 is ,produced -by spring means such as a spring 118 connecting the upper arm of bell crank v112 with aiixed part which forconvenience is shown-as .pin 103. A rearwardly .extending arm 119 is xed with respect to arm117 and has, an adjustable spring connection with a rearward projection 120 of arm 104.

Suction tingers 32 aremoved back and forth between their discharge positions `(Fig. 6) andtheir pick-oppositions (Fig. 7). To this end each suction finger 32 is clamped in a block 125 (Fig. 2) slidable along a rod or shaft (126 but held against turning thereabout by -a .set screw 1-26a projectingrinto a longitudinal groove 127 or slot-in the shaft. Saidshaft 126 is mounted `to turnin the upper ends, of membersor arms 128 fixed at their lower endson a shaft :113. An -arm 130 fixed on said shaft 113isoperatedby said ,inner cam 59 to swing arm .123 from itslower (Fig. 7) position to pick up a sheet 26 from'the stack i25.to.its .upper (Fig. 6) position toplace the leading edge of the sheet between feedroll 33 and a cooperating roll 131 forming .part of a device which assists in controllingthe action of the ejector plate 37.

Duringthe Vupwardmovement of lshaft 126, a follower 132 at the outer end of an arm 133 fixed on shaft126 rides upon a cam 134 onthe front frame ofthe machine (Figs. 2 and 7), and thepick-up iingers 32 are turned in aclockwise-.direction against the resistance of tubes 134a of suitable resilient material connecting `saidpickup lingers ,32 to a transverse tube or header 134b.

At the Afront frame, said transverse tube 134b-is closed by a plug`134c, and at the rear frame said tube 134b is connected through an elbow 135 .with the suction end of an air pump .136 drivenby a motor 137 (Fig. l). The connection between said elbow 135 and the suction end of `said pump 136 comprises a flexible tube '138, a valve device 139 and a flexible tube 140. Said valve device 139 comprises a hollow body 141 having a ilat side provided with inlet ports 142 and 143 which are controlled by plates or valves 1144 and 145 respectively, mounted on pivot screws 146 and 147. Springs 148 and 149 on screw pivots 146 and 147 urge said valves against 'their seats.

Valve 144 is operated mechanically through a link 150, an arm 151 having at its lower end a pivot 152 projecting through a slot 153 in said link 150, and said shaft 113 on the rear end of which the upper end of said arm 151 is fixed. The arm 151 (Fig. 16) is urged in a counterclockwise direction (Fig. 4) by a tension spring 155 connected at one end to arm 151 and at the other end to a fixed member such as a pin 156. When the suction pickup members 32 are in position to pick up a sheet, valve 144 is closed and the pump draws air out of the suction pick-up member or fingers 32 and lifts the uppermost Sheet from the stack, arm 151 is swung clockwise and, when the pivot 152 engages the left end of said slot 153 and opens the valve 154 thus breaking the suction action at said suction fingers or nozzles, the sheet is released in position to cooperate with the feed roll 33. Air is forced from the pump 136 through a duct 160 such as a flexible hose and through branches 161 to jet nozzles including a central nozzle 162 having a discharge outlet 163 (Fig. 17) to act on the forward edges of sheets at the top of the stack.

Other branches 161 lead to additional air jet devices such as side nozzles 165 located at the sides of the stack near the forward edges of the sheets and having side outlets 166 (Fig. 6). Said side nozzles 165 are supported in the forward ends of arms or brackets 167 fixed on slides 168 in the form of blocks mounted on a shaft 169 held against rotation and about which said sprockets 62 rotate. Said slides 168 are held against rotation on said shaft 169 by set screws 176 extending into -a groove 171 but can slide along said shaft. Preferably said side nozzles 165 are frictionally supported in brackets 167 so that they can readily be adjusted vertically and rotationally.

In order to get full benefit of the air currents particularly when starting, the air flow into the suction ngers and out of the air jets adjacent to the top sheets of the stack, should be established `before the first sheet is picked up. This result may be attained by holding valve 145 (Fig. 5) open manually until the proper current of air is established. This may be done by opening valve 145 manually and holding it open as long -as desired. When the air iiow is established valve 145 may be closed.

Such manual control may involve the use of a link 175 connecting a pivot 176 on valve 145 with -a pivot 177 on an arm 178 extending downwardly from the rear end of a shaft 179 extending to the front of the machine. Mounted on shaft 179 at the front of the machine is a handle 180 (Figs. l, 4 and 6) by which the shaft can be operated.

From said slides 168 guide members 181 extend downwardly along the sides of the stack 26 substantially parallel to said guides or rails 29 and into a slot 182 in the bottom 183 of the elevator 27 (Fig. 17).

Mounted on said shaft 169 is a central slide or block 185 adjustably secured to the shaft 169 by means of a set screw 186. Pivoted on said shaft 169 is a yoke 187 enclosing said block 185 and having at the ends of the sides of said yoke teeth or lugs 188 to engage at opposite sides of the block stops 189 which may be the ends of a pin passing through the block 185.

A rod 19t) is secured at one end to the cross piece of said yoke 187 and carries a device 191 (Fig. 16) to engage the rear face of the stack 25 and prevent displacement of the sheets rearwardly. Said device 191 comprises a collar 192 slidable on said rod 190 and provided with a set screw 193 to hold the collar 192 in any' selected position, and a plate 194 having an upturned triangular forward portion with an opening receiving said of arms 197 to limit the downward movement of arms 197. In ordinary operation the arms 197 are in their Fig. 16 positions. If the elevator rises so far that it engages arms 197, they will be swung upwardly about their pivots and will continue to engage the back face of the stack 25.

The upper sheets 26 of stack 24 are held against sidewise displacement by fingers 200 at opposite sides of the stack and slidably mounted on rods 201 pivoted at their forward ends on slides or blocks 168.

At the forward face of the stack, there is a transverse or cross member 210 supporting two devices for separating the forward edges of sheets. Each of these devices for separating the forward edges of sheets comprises a strip or strap 212 of material such as metal extending downward at the rear surface of said member 210. At a point above the upper edge of each member 210, each strip 212 is secured by means including two bolts 213 to a supporting member such as a bar or block 214. A thin resilient member or spring 215 is secured to the supporting member or bar by a spacing member 211 and a relatively stiff sheet or outer member 216. Said spring 215 is tapered above the edge of block 214 and inclined rearwardly into a notch 217 through which its sharp edge 218 projects.

Along the inclined part of said spring the shank of a screw 220 extends through a hole in the spring and the head engages the spring 215 from the rear. The shank of the screw 220 is threaded into member 216. By inserting a screw driven through hole 221 in strap 212 the screw 220 can be operated to adjust the position of said sharp edge 218. When a sheet is lifted by the suction fingers 32 the forward edge snaps over edges 218 and is separated from the next lower sheet. The position of said sharp edges 218 may be varied to meet the requirements.

At the forward edge of the floor of elevator 27 there are two separate floor members 223 adjustable along the forward edge of the elevator oor to accommodate different widths of sheets. Each of said parts 223 is in the form of an angle-one side of which is an extension 224 of the upper face of the elevator oor and the other side 225 engages the forward wall 226 of the elevator floor. For guiding purposes, said sides 225 have tongues 227 struck out and passed through a corresponding slot 228 in wall 226.

For additional guiding and also for clamping, use

is made of screw threaded studs 229 secured as by riveting to side 225 and projecting through slots 230 in wall 226. Nuts 231 on said threaded studs 229 may be used to clamp said floor parts or members 223 in adjusted position. A sheet of paper on its way from the stack to the feed rolls 33 and 35 and over ejector member or plate 37, is held against upward movement at its edges by guides or bars 235 secured at their rear ends to brackets 167 carrying the side nozzles 165. Said guides extend over said feed rolls and also over the ejector plate to assure downward deflection of ejected sheets or groups of sheets.

As shown clearly in Figs. 7 and 8, a device for pressing sheets 26 against feed rolls 33 and 35 for effecting a satisfactory friction drive and for controlling means for ejecting multiple sheets is mounted on said hollow shaft or air duct 134b, a parallel rotative shaft 240 and a parallel fixed shaft 241. Two frame members 242 are mounted on said shafts 134]), 240 and 241. Mounted on pivots 243 are levers 244 carrying at their rear ends said roll 131. A spring 245 is connected at its lower end to the forward end of one of said levers 244 and at its upper end to a fixed pin on one of said frame pivoted at its lower end to the forward end of the lever 244 to which spring 245 is connected. A pin 247 extends through a slot 248 and is secured in one frame member 242. Said slot 248 has a-vertical partand a horizontal partat-the upper end of said vertical part. Spaidspring 2.45 normally keeps pin 247 inthe lower end ofthe verticabparts of the slot'but roll 131 can be rajsedgancl'heldraisedby pressing the plunger 246 down until the horizontal part of the slot is opposite -pin 247 and then'prcssing the plunger rearwardly so that the heriztontalffparttof the :slot contains tbe pin. The-plunger .may be released by moving it yforwardly and roll 131 will return to effectiveV position. Balls 250 in iframes 2.5.1 -veenneeted-with :frames 4.24.2 keep-the sheets in suiteblefenaagement with rQ1135.

.'lhaframe members 24.2:are connected Iby cross. members .ligand screws 4253. with frame-member .254 (Eis- St). At-.the -top `.of .frame member `254 a vbleek 25.5 istpivetally :supported by'meaos .of a pin 256. The bleek .255. has va bere therethrough .containing a red 2.58 the upper vend fof which is .screw :threaded and Carries-a 11111259. Below bleek 25.5 Yamelie-a1 Compressionspring 250 surrounds said rod 258 and is compressed between block 255 and a pivotalfconnection 261 between rod 258 and an arm 262 xed on shaft263. A round member .264 .on .shaft'263 is mounted Vfor turning in a bearing in frame member 2.54. Eeeentreallv mounted on the end of round `.member 264'is .a detector member T34 being mounted en. a :pivot ..266 eccentrically mounted in the end of member 2.64.

all will V be seenfthat byediustmg the nut 2.59 the distanceof the Pivot 266 from the top yof feed roll 33h-may be determined. AThe spring 260 urges the pivot ..26610- ward theftop of the feed roll 33 but by adjusting ythe Inut 259 the pivot 266 may be kept at the desired distance frotnthe toprof roller 233. The detector member 34 has an upwardly projecting part 267 normally held in engagement-Miha Pin 268 projecting from frame member v.254...

by means of a spring 269 connecting a pin 270 on the j detector member 34 with a pin 271 on the frame member l2 54. `'['he lower part of said detector 3 4` is relatively broad asshown in Fig. `8 and is normallylocated immediately abovefeed roll 33. To the rear of the roll 233 the broad part of the detector member is cut away as shown in` Fig. l2.

At theforward silde'of pivot 266 the detector is provided witha downwardly turned hook 273 which engages the lower upturnedend of a hook 274, the upper end of which is secured on a shaft 240. Said shaft 240 is iprovided at its `front end with a downward extending arm 275 v(f1 `ig.;? .\)v. The lower end of army275 is connected by a generally horizontal link 276 with the upper arm of `a lever .277. Ihe lower end of said lever 277 is connected by a .generally horizontal link 278 with an upwardly extending arm 279 of a bell crank 280 of which a second arm 281-rnay he lactuated by a device 282 on the rear cam 59..car1 ied by the cam shaft 56. The upper arm of lever 277 is urged toward a pin 283 connecting'the endL of said lever 277 with a fixed pi11285. Normally said hookY 274 is `locked in position by Said hook 273 andthe arm 28j1 of the bell crank 280 will be held out of thepath of the stud 282 which may be in the form of a pin with a sleeve rotatably ymounted thereon to avoid friction.

When a plurality of sheets passes between the detector 34 and the forward roll 33 `the detectorwill be thrown from its normal position shown in Fig. l2 to the position shown in #Fig- 1..3 :and the rivet 26.6 will be .raised againstthe action of spring 260. In `this movement the hook 273. is lifted and releases the hook 274, thus allowing the spring 2'84-to act through the various conneotions and lower arm V2781 of bell crank 2 8() into a position to he actuated by stud 286. The hook 274 will then be swung towardthe detector 34. The lever 277 .is mountedl on shaft- :41 on which yare mounted two brackets 40 carrying the ejector plate 37. The release of said hook 274, vwll cause the detector plate .to move from its full line position (Fig. A12) to its dotted line position and `will direct a group of multiple sheets downwardly to a chute 42. When the .multiple sheets have passed the feed roll 33 the Vdetector 34 mayreturn to its-original position and subsequentiactuation ofbell crank v280 by stud 286-will causethe hook 274 to pass beneath the-hook 273to-lift the latter enough for hook 274 to be lockedlby hook 273 when it reaches its full line position in Fig. l2.

In operating the machine a stack 25 of sheets '26fisin position on the elevator 27 which is positioned approximately at the proper level for removal of the top sheet bythe suctionfpick-up fingers 32. The slides k168 are adjusted on transverse shaft 169 so as to engage thesides of the stack and members 212 are adjusted along the member 210 at the forward side of the stack to the proper positions between the sides of the stack so that fingers 218 will serve to separate the sheets when'lifted'lby the suction lingers 32.

The suction `pick-up lingers 32 are adjusted along-trans-A fer shaft '126 to come to positions suitably related to the sheets separating members 213. Also the central jet member 162 and theside jet members 165 are set at suitable positions so that they will tend to lift the uppermost sheet at its forward edge and at its sides near its forwardfedge. When suction pick-up fingers are lowered to a position immediately above the uppermost sheet on the stack, the valve 144 will be closed So as to make the suction action effective and the forward edges of the'sheets'will be placed between the feed roll 33 and the cooperating roll 131. lf only one sheet is fed to the feed roll 33 it will ordinarily pass over the second feed roll 35 and under balls 250 which assure suitable frictional contact of the sheets with feed roll 35. From the feed roll 3S the sheet will normally pass over the ejector member 37 and pass tothe bands or belt leading to the printing machine. i

In connection with starting the operation the motor 137 is thrown into operation to operate the pump 36 which drawsiin air through the suction pick-up finger 32 andy drivesair out through the air jet devices 162 and 165. By means of the handle the valve 145 in the air duct may be held open so that no suction will be produced at the suction pick-up fingers. By opening the suction line in `this way the regular current of air through the `air ducts is established and after that occurs and themachine proper is started, the handle 180 may be restored to its normal position and the suction regulated by the valve 144 which is mechanically opened and closed.

lThe elevator will be raised whenever the level of the sheets in the stack is below a predetermined level but when the uppermost sheet is at or above the predetermined level the lifting of the stack will be eliminated until the uppermost sheet again comes below the :predetermined level.

When a plurality of sheets is passed between the feed roll 33 and the detector 34, the hook 273 is raised and unlocks hook 274. The spring 284 then acts to shift the deflecting plate or ejector 37 to inclined position to Adirect the sheets downwardly to chute 42 and to shift bell crank' lever into position for its arm 281 to be engaged by stud 286. Such engagement will restore ejector plate 37 to its normal position and cause lhook 274 to be locked in Vits normal position. The machine will then be in condition for normal operation.

The shapes of feeler-lifting cam 57, pick-up finger cam 59 and elevator-lifting cam 58 should be noted. Cam 59 has a high dwell portion and a short concave portion of which the ends merge smoothly with the high dwell portion. As a result of the shape of cam 59, the pick-up fingers 3 2 are heldin their high positions during the greater par-t of a revolution of cam shaft 56, and in-the remainder of the revolution are dropped rather quickly to pick up a sheet 26 and then lifted rather quickly to their high positions to feed a sheet to a. feeding roll and cooperating device.

The feeler-lifting cam 57 may be of the same shape as cam 59 but is somewhat advanced on shaft 56 .sothat the feeler 31 goes down before the pick-up fingers drop and is lifted before the pick-up fingers are lifted, thus avoiding any resistance by th.; feeler to the upward movement of a sheet 26 picked up by said pick-up fingers 32.

Elevator-lifting cam 58 has a high dwell portion extending about half way around the periphery and a portion gradually decreasing in height from both ends toa central low point. The pawl carrier 74 will then be held in advanced position by the cam for a substantial part of a rotation of the cam shaft 56, and when the return movement of pawl carrier 74 is limited by pawl 99, the high part of cam 58 will advance the pawl carrier sufficiently to release the pressure on pawl 99 and facilitate movement thereof to ineffective position by feeler controlled means.

It should be understood that various changes may be made and that certain features may be used without others, without departing from the true spirit and scope of the invention.

What is claimed is:

l. A sheet feeder for a printing press comprising stack raising means to present top sheets at proper levels for removal, means to hold the sheets in proper position in their planes, means to act on the uppermost sheets to facilitate their removal from the stack, a plurality of feed rolls, means above said feed rolls to hold said sheets on said rolls, a feeler operated to ascertain the position of the uppermost sheet, means controlled by said feeler for rendering said stack raising means ineffective when the top sheet of the stack is too high and effective when no sheet is above the required level, means including suction pick-up fingers for delivering top sheets to the first feed roll, said stack raising means comprises a platform, means including upwardly extending guides for said platform, sprockets at the upper ends of said guides, sprocket chains connected to the ends of said platform and extending over said sprockets and downwardly, a transverse shaft, other sprockets xed on said shaft engaging the downwardly extending parts of said sprocket chains, a ratchet wheel, speed reducing gearing from said ratchet wheel to the shaft for the lower sprocket wheels, a pawl carrier movable about the same axis as said ratchet Wheel, an actuating pawl for said ratchet wheel on said pawl carrier, a holding pawl for said ratchet, an actuating arm operatively connected to said pawl carrier, a moving cam acting on said arm, a spring urging said arm toward said cam, a pawl spring-pressed against said pawl carrier to limit rearward movement of said pawl carrier to less than one tooth whereby the actuating arm will be shifted slightly out of the path of said cam during part of a revolution of the cam and then the actuating arm will be' struck by the cam to relieve the pressure on the pawl engaging the pawl carrier, and an arm on said feeler to release the pawl-carrier retaining pawl.

2. A sheet feeder for a printing press comprising stack raising means to present top sheets at proper levels for removal, means to hold the sheets in proper position in their planes, means to act on the uppermost sheets to facilitate their removal from the stack, a plurality of feed rolls, means above said feed rolls to hold said sheets on said rolls, a feeler operated to ascertain the position of the uppermost sheet, means controlled by said feeler for rendering said stack raising means ineffective when the top sheet of the stack is too high and effective when no sheet is above the required level, means including suction pick-up fingers for delivering top sheets to the first feed roll, said stack raising means comprises a platform, means including upwardly extending guides for said platform, sprockets at the upper ends of said guides, sprocket chains connected to the ends of said platform and eX- tending over said sprockets and downwardly, a transverse shaft, other sprockets fixed on said shaft engaging the downwardly extending parts of said sprocket chains, a ratchet wheel, speed reducing gearing from said ratchet wheel to the shaft for the lower sprocket wheels, a pawl carrier movable about the same axis as said ratchet wheel,

an actuating pawl for said ratchet wheel on said pawl carrier, a holding pawl for said ratchet, a hand wheel connected to said ratchet wheel, lateral releasing projections on said actuating and holding pawls, a curved lever arm on the pivot of said holding pawl at the inner sides of said projections to release said pawls when swung outwardly, a second lever arm on the same pivot as the first lever arrn, and spring means connecting said lever arms, whereby movement of said second lever arm to release said actuating and holding pawls will stress said spring and upon releasing the pressure on said pawls by manual actuation of said hand wheel, the curved lever arm under pressure by said spring means will engage said projectionsy and render the pawls ineffective so that said platform may be moved up and down by said hand wheel.

3. A sheet feeder for a printing press comprising a support for a stack of sheets, means for elevating said platform to place the uppermost sheets \in proper position for removal, sheet advancing means and means for picking up sheets one by one from said stack and supplying them to said advancing means comprising suction fingers, a transverse shaft, slides adjustable along said shaft and rotatable therewith, said suction fingers being clamped in said slides, a second shaft, arms fixed on said second shaft and provided at their outer ends with bearing receiving the first mentioned shaft, means for swinging said arms upwardly and forwardly, an arm fixed on one end of the slide-carrying shaft, a follower on said arm and a fixed cam engaged by said follower and acting to turn the slide-carrying shaft to swing said suction fingers in clockwise direction to the sheet delivery position.

4. A sheet feeder for a printing press comprising a support for a stack of sheets, means for elevating said platform to place the uppermost sheets in proper position for removal, sheet advancing means and means for picking up sheets one by one from said stack and supplying them to said advancing means comprising suction fingers, a transverse shaft, slides adjustable along said shaft and rotatable therewith, said suction fingers being clamped in said slides, a second shaft, arms fixed on said second shaft and provided at their outer ends with bearings receivring the first mentioned shaft, means for swinging said arms upwardly and forwardly, an arm fixed on one end of the slide-carrying shaft, a follower on said arm, means to raise said suction fingers and turn them counterclockwise to delivering position, a transverse header and resilient flexible tubes connecting said suction fingers to said header.

5. A sheet feeder for a printing press comprising a support for a stack of sheets, means for elevating said platform to place the uppermost sheets in proper position for removal, sheet advancing means and means for picking up sheets one by one from said stack and supplying them to said advancing means comprising suction fingers, a transverse shaft, slides adjustable along said shaft and rotatable therewith, said suction fingers being clamped in said slides, a second shaft, arms fixed on said second shaft and provided at their outer ends with bearings receiving the first mentioned shaft, means for swinging said arms upwardly and forwardly, an arm fixed on one end of the slide-carrying shaft, a follower on said arm, means to raise said suction lingers and turn them counterclockwise to delivering position, a transverse header, resilient flexible tubes connecting said suction fingers to said header, blowing devices at each side of the stack to aid in separation of sheets and supports for said blowing devices adjustable to conform with widths of the stack.

6. A sheet feeder for a printing press comprising a support for a stack of sheets, means for elevating said platform to place the uppermost sheets in proper position for removal, sheet advancing means and means for picking up sheets one by one from said stack and supplying them to said advancing means comprising suction fingers, a transverse shaft, slides adjustable along said shaft 11w and rotatable therewith, said suction fingers being clamped' in' said slides, a second shaft, arms fixed on' said second shaft and provided' at their. outer ends with bearingsreceiving the first mentioned shaft, means for swinging said arms upwardly and forwardly, an arm xed on one end of the slide-carrying shaft, a follower on` saidl arm, means to raise said suction fingers and turn them countercloekwise to delivering position, a transverse header and resilient flexible tubes connecting said suction fingers to said header, blowing devices at each side of the` stack to aid in separation of sheets, supports for said blowing devices adjustable to` conform with Widths of theV stack, an air pump, a suction duct connecting said,

header with the suction side' of said pump and branch ducts connecting said blowing devices with the discharge end of said air pump;

7. A sheet feeder for al printing press comprising' a support for a stack of sheets, means for elevating saidv platform to place the uppermost sheets in proper position for removal, sheet advancing means and means for picking up sheets one by one from said` stack and supplying them to said advancing means comprising suction fingers, a transverse shaft, slides adjustable along-Y said shaft' andI rotatable therewith, said suction fingers being clamped in said slides, a second shaft, armsfixedV on= said second shaftand provided' at their outer endz`s=wi`tl`1` bearings receiving the first mentioned shaft, means`- forv swinging said arms upwardly and forwardly, an arm fixed on one end of the slide-carrying shaft, a follower on said arm, meansy to raise said suction fingers andI turnl them counterclock-wise to deliveringy position; a transverse header, resilient flexible tubes connecting said suction fingers to said' header, blowing devices at each side of the stack to aid in separation of sheets, supports-for said blowing devices adjustable toconform with widths-of the stack, a valve in said suction duct, andl means for closing said valve as the suction ngers are about to' contact a sheetin the stack. and remaining closed until the sheetl is fed tothe sheet advancing means and to-lteepYA the-valve open during the downward movement of the suetionfingers.

8. A sheet feeder for a printing pressi comprising a support for av stack of sheets, means for elevating vsaidv platform to place the uppermost sheets in proper position for removal, sheet advancing means and means for picking up sheetsl one by one from said stack andi supplying them to said advancing means comprising suction fingers, a transverse shaft, slides adjustable along` said? shaft and rotatable therewith, said suction fingers being clamped in said slides, a' secondshaft, arms fixed on said second shaft and provided at their outer ends with bearl2 ings receiving the first mentioned shaft, means for swinging said arms upwardly and forwardly, anY arm fixed on one end" of: the slide-carrying shaft, a follower on said" arm, means' to raise said suction fingers and turn them counterckzlockwise` to delivering position, a transverse header and resilient exible tubes connecting said suctionfingers'to saidheader, blowing devices at each' side` of the stack to aid in' separation of sheets, supports for said blowing' devices` adjustable to conform with widths of the stack, aA valve in said suction duct, means' for closing said valve as the suction fingers are about to contact a sheet in the stack and remaining closedl until the' sheet is fed to the sheety advancing means and to keep the valve openv during the downward movement of the' suctionfingers and a second manually controlled valve to be held open' until the proper air flow is established in the air flow system.

9`. A sheet feeder for a printing presscomprising` an elevator for a stack of sheets, a cross member extending across the front of said stack, devices slidably mounted onthe upperedge of said member and comprising strips with their upper ends raised above4 the upper edge of said cross member and extending downwardly to the lower part of the path of the elevator, each of said strips having a central notchI at its upper end, a supporting, memher secured to said strips and engaging they upper edge of said cross member, al fiat spring back of saidv supporting member inclined rearwardly from the upper edge of said supporting member and tapered at both sides to provide a sharpr edge projecting through one of` saidI notches, ay spacing member and a stiff sheet member at the forward' sideof the supporting member, bolts' extending through the upright strip, the supporting member, the spring andthe stiff sheet, and an adjusting screw extending'- through a hole in the inclined portion of said spring and threaded into said stiff sheet, said main strip having a hole exposing the headV of said adjusting screw, said sharp edge acting to separate the forward edges of the sheet.

References CitedA in the file of this patent UNITED STATES PATENTS 625,094 Dexter May 16, 1899 11,600,959 Henderson Sept. 21, 1926i 1,762,661 Low June 10, 1930 2`f`,22O,(Y73j Belcher Nov. 5, 1940 2,230,633 Williams Feb. V4, 1941 21,287,140 Schnedier Iune`23, 1942 2,374,578 Bernard Apr. 24, 1945 2,479,060- Davidson Aug, 16, 1949 2,6'60;113l Gullixson et al Nov. 24; 1953' 

